Adjustable mower suspension system

ABSTRACT

An electric drive riding lawn mower includes a pair of electrically driven rear drive wheels and steerable front wheels controlled by a steering wheel mounted in an upright supporting structure at the forward end of the machine. A rotary mower unit is suspended from the main frame between the front and rear wheels and includes a generally horizontal housing connected to the main frame by front and rear links which permit the vertical movement of the mower unit between a lowered operating position and a raised transport position. The position of the mower unit is controlled by a lever pivotally mounted alongside the support structure and connected to the mower unit by a cable, the control lever being lockable in a rearward position wherein it maintains the mower unit in its raised position, and swingable forwardly to lower the mower unit. An adjustable stop limits the forward movement of the control lever to establish the lowermost, operating position of the mower unit.

llnited States Patent [191 Behrens ]March 20, 1973 [54] ADJUSTABLE MOWERSUSPENSION SYSTEM [75] Inventor: Robert Nick Behrens, Horicon, Wis.

[73] Assignee: Deere & Company, Moline, Ill.

[22] Filed: Oct. 4, 1971 [21] Appl. No.: 186,243

Primary Examiner-Louis G. Mancene Assistant Examiner-J. N. EskovitzAttorney-H. Vincent Harsha et a1.

[ ABSTRACT An electric drive riding lawn mower includes a pair ofelectrically driven rear drive wheels and steerable front wheelscontrolled by a steering wheel mounted in an upright supportingstructure at the forward end of the machine. A rotary mower unit issuspended from the main frame between the front and rear wheels andincludes a generally horizontal housing connected to the main frame byfront and rear links which permit the vertical movement of the mowerunit between a lowered operating position and a raised transportposition. The position of the mower unit is controlled by a leverpivotally mounted alongside the support structure and connected to themower unit by a cable, the control lever being lockable in a rearwardposition wherein it maintains the mower unit in its raised position, andswingable forwardly to lower the mower unit. An adjustable stop limitsthe forward movement of the control lever to establish the lowermost,operating position of the mower unit.

9 Claims, 4 Drawing Figures PATENTEDMARZO ma 3,721,076

INVENTOR.

R. N. BEHRENS AllMlUSTABLE MOWER SUSPENSION SYSTEM BACKGROUND OF THEINVENTION This invention relates to a tractor-mower unit, and moreparticularly to a mechanism for suspending the mower unit from thetractor.

It is conventional in lawn and garden tractors or the smallertractor-mower units of the type known as riding mowers to suspend themower unit between the front and rear wheels of the vehicle, and furtherto provide means for raising and lowering the mower unit.

In many prior suspension devices, the mower unit rides on the groundduring the mowing operation and is raised only for transport. This typeof suspension requires adjustment of gauge wheels and the like to varythe cutting height of the mower. In many other machines, the mower unitis suspended from the tractor and its height is controlled by amanually-actuated linkage which is lockable in different positions toestablish the different cutting heights, which vary in increments.

SUMMARY OF THE INVENTION According to the present invention, an improvedsuspension system is provided for suspending a mower unit from a ridingmower or the like. More specifically, the suspension system providesmeans for easily raising and lowering the mower unit between a raisedtransport position and a lowered operating position, wherein the mowerunit is entirely supported on the vehicle.

An important feature of the invention resides in the provision of meansfor easily adjusting the operating height of the mower unit ininfinitely variable positions.

Another feature of the invention resides in the use of a cable-typemechanism for suspending and raising and lowering the mower unit.

Still another feature of the invention resides in the location of thecontrol lever of the suspension mechanism on the steering column of theriding mower, wherein it will not interfere with other components on themachine and is easily manipulated by the operator, and further inproviding adjusting means on the steering column for adjusting thecutting height of the mowing unit, even during the operation of themower.

Still another feature of the invention resides in the simple and ruggedconstruction of the suspension mechanism and the means for adjusting thecutting height.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation view of ariding lawn mower with portions of the front and the rear of the ridingmower removed and with the mower unit shown in its raised position, thelowered operating position of the mower unit being shown in dottedlines.

FIG. 2 is a side elevation view of part of the control mechanism for thesuspension of the mower unit, the control mechanism being shown in itslowered operating position.

FIG. 3 is an enlarged side elevation view of the mechanism for adjustingthe cutting height.

FIG. 4 is a plan section view of a portion of the steering column asviewed along the line 4-4 of FllG. ll.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is embodied in ariding mower having a mobile main frame, indicated in its entirety bythe numeral It) and mounted on a pair of steerable front wheels 12 andrearward drive wheels 14. The drive wheels are driven by abattery-powered electric drive system (not shown) disposed in a housing15 on the rearward portion of the vehicle. An operators seat (not shown)is conventionally mounted on the forward part of the housing 15, so thatthe operators seat is behind a generally upright support structure orsteering column 16 at the forward end of the vehicle. The supportingstructure 16 is hollow and includes a pair of opposite sidewalls IS, anupwardly and rearwardly inclined front wall 20, and a rear wall 22. Asteering wheel 24 is disposed at the upper end of the support structure16 and is connected to the front wheels 12 through a conventionalsteering mechanism. The seated operator, of course, manipulates thesteering wheel and rests his feet on a platform 26 on the opposite sidesof the support structure 16 and forwardly of the housing 15.

A rotary mower unit, indicated in its entirety by the numeral 30, issuspended from the main frame and includes a generally horizontalhousing or deck 32, which, as is conventional, is open toward the bottomand has a discharge opening at the right side of the unit. A pair ofhorizontal cutting blades 34 are directly mounted on the shafts ofelectric motors 36, which are powered by the same batteries as the mainvehicle drive. A horizontal transverse roller 38 is mounted at the frontof the housing 32 to prevent the blades from scalping the turf onirregular terrain, and a pair of rear antiscalping wheels 40 aresimilarly mounted at the rear of the housing to raise the mower unitover raised portions of the turf.

The mower unit 30 is suspended from the main frame for generallyvertical adjustment between a raised or transport position, as shown infull lines in FIG. 1, and a lowered or operating position, as shown indotted lines, by means of a parallelogram linkage, which includes a pairof transversely spaced, generally fore-and-aft links 42, having theirfront ends connected to a transverse pivot 44 carried by the main frameand their rearward ends connected to a transverse shaft 46 mounted atthe forward end of the mower housing 32, only the righthand link d2being shown in FIG. l. The rearward portion of the parallelogram-typelinkage is formed by a generally fore-and-aft rear link 4% having itsforward end pivotally connected to the main frame at 50 and its rearwardend connected to a transverse shaft 52 journaled in a bracket 54connected to a rearward end of the housing 32.

A tension spring 56 has its forward end connected to the housing 32 andits rearward end connected to an arm 58 extending radially from theshaft 52, so that the spring force tends to rotate the shaft 52 andraise the mower unit, thereby partly counterbalancing the weight of theunit. The mower unit is maintained in a level condition by aparallelogram-type linkage which includes a front leveling arm 66)extending radially upwardly from the shaft 46 and a rear leveling arm 62extending radially upwardly from the rear pivot shaft 52, the arms 60and 62 being interconnected by an adjustable link 64, the length ofwhich is adjustable to vary the attitude of the mower unit.

Mounted alongside the support structure 16 is an elongated, generallyupright control lever 66, which is swingably mounted on a transversepivot 68 extending outwardly from the right sidewall 18 of the supportstructure. An abutment sleeve 69 is mounted on the pivot 68 within thesupport structure 16, and the control lever has an offset portion 70immediately below the pivot 68, the lower end of the control leverextending inwardly through a slot 72 in the right sidewall 18 to theinterior of the supporting structure. The lower end of the control leveris provided with a transverse pivot 74, to which is connected theforward end of a suspension cable 76, which is trained around a framemounted pulley 78 and has its other end connected to the mower housing32.

The upper end of the control lever 66 is provided with a handle 80. Asis apparent, the weight of the mower unit tends to rotate the controllever in a clockwise direction to move the handle 80 forwardly, and themower unit is raised by pulling rearwardly on the handle 80 and loweredby allowing the handle 80 to move forwardly. A latch 82 is mounted onthe right sidewall 18 of the support structure and is operative toreleasably lock the control lever in its rearward position, as shown inFIG. 1, wherein it maintains the mower unit in a raised position. Asbest shown in FIG. 4, the latch 82 is formed by an angled member securedto the support structure sidewall and having a cam surface 84 generallyparallel to the sidewall and a transverse abutment 86 at the rear of thecam surface. As the control lever is swung rearwardly, it engages thecam surface 84 and is shifted outwardly until it clears the rearward endof the latch, whereupon it springs toward the support structure andengages the abutment 86, which prevents forward movement of the controllever. To release the latch, the control lever is simply deflectedlaterally until it clears the abutment 86 at which time the raised mowerunit will tend to move it forwardly.

An elongated, generally vertical member or arm 87 has its lower endpivotally connected to the lower end of the control lever 66 by means ofthe pivot 74, while the upper end of the arm 66 is positioned by anadjusting mechanism, indicated in its entirety by the numeral 88. Theadjusting mechanism includes a threaded foreand-aft extending rod 90extending through and journaled in the rear wall 22 of the supportstructure and having a handle 92 at its rearward end to facilitaterotation of the rod. The forward end of the rod extends through athreaded bore 94 in a transverse pivot 96 carried at the upper end ofthe arm 87, which is preferably bifurcated to support the pivot 96. Ahelical compression spring 97 around the rod 90 operates between thesupporting structure and a nut 98 on the threaded rod to maintain thefore-and-aft position of the rod relative to the support structure. Asis apparent, rotation of the rod 90 via the handle 92 causes the upperend of the arm 87 to move forwardly or rearwardly, depending upon whichdirection the rod is rotated.

In operation, the mower unit is raised by pulling rearwardly on thecontrol lever 66 and holding the lever in its rearward position by meansof the latch 82 as previously described. When the upper end of thecontrol lever is shifted laterally to clear the latch and allowed tomove forwardly, the lower end of the control lever swings rearwardly,allowing the cable to move rearwardly and the mower unit to lower.However, the rearward movement of the lower end of the control leveralso causes the lower end of the arm 87 to move rearwardly about thepivot 96 until the arm engages the sleeve 69 on the pivot 68, as shownin FIG. 2, at which time further movement of both the arm and thecontrol lever is stopped, thereby stopping the downward movement of themower unit. The position of the arm 87 when it engages the sleeve 69depends on the location of the upper end of the arm. Thus, by moving thepivot 96 rearwardly via the adjusting mechanism 88, the lower end of thecontrol lever and the lower end of the arm 87 would not be allowed tomove as far to the rear before the arm engages the sleeve 69, so thatthe mower unit would not drop as far. Conversely, shifting of the pivot96 forwardly allows greater motion of the lower end of the control leverbefore the sleeve 69 is engaged to limit additional movement. In thedrawings, the pivot is shown in its forwardmost position, so that themower unit, when lowered, is disposed in its lowermost position. As isapparent, the cutting height of the mower unit can thus easily beadjusted into infinitely variable positions by simply rotating thehandle 92, even when the mower is operating.

I claim:

1. In a riding lawn mower having a mobile main frame supported on frontand rear wheels and a mower unit suspended from the main frame betweenthe front and rear wheels and including a generally horizontal housing,the improvement comprising: linkage means extending between the mainframe and the housing and operative to permit generally verticalmovement of the mower unit while maintaining it in a generallyhorizontal condition; a manually adjustable lever means mounted on themain frame for swinging in opposite generally fore-and-aft directions; acable means operatively interconnecting the lever means and the mowerunit so that the mower unit is raised in response to the movement of thelever means in one direction and lowered in response to movement in theopposite direction; latch means operatively associated with the levermeans for releasably locking the lever means in a raised positionwherein it maintains the mower unit in an elevated condition above theground; a stop means operatively communicating with the lever means forlimiting the movement of the lever means in said opposite direction andthereby establishing the lowermost position of the mower unit; andadjustment means operatively connected to the stop means for selectivelyadjusting the position of the stop means and varying the lowermostposition of the mower unit.

2. The invention defined in claim 1 wherein the stop means includes anabutment on the main frame and an adjustable member connected to thelever means and engageable with the abutment to limit the movement ofthe lever means, and the adjustment means is operatively associated withsaid adjustable member to vary the position of the adjustable member andthereby vary the position of the lever member when the adjustable memberengages the abutment.

3. The invention defined in claim 2 wherein the adjustable member ispivotally connected to the lever means for swinging about an axisparallel to the lever means pivot axis and the adjustment means includesa rotatable threaded rod operatively connected to the adjustable memberfor swinging the member about its pivot axis in response to rotation ofthe rod.

4. The invention defined in claim 3 wherein the lever means includes agenerally upright control lever swingably mounted on a transverse pivotfor swinging in a fore-and-aft direction and the adjustable member isvertically elongated and has its lower end connected to the controllever and its upper end connected to the threaded rod for adjustment ina fore-and-aft direction, the control lever pivot forming the abutmentwhich engages an intermediate portion of the adjustable member to limitthe movement of the adjustable member and the control lever connectedthereto.

5. In a riding mower having a mobile main frame including a generallyupright support structure at the forward end of the machine and a mowerunit suspended from the frame via linkage means which permits verticaladjustment of the mower unit between a lowered operating position and araised transport position, the improvement comprising: a generallyupright control lever mounted on a transverse pivot on the supportstructure for swinging in a fore-andaft arc; a connecting means betweenthe lower end of the control lever and the mower unit for respectivelyraising and lowering the mower unit in response to rearward and forwardswinging of the control lever; a latching means for releasably holdingthe control lever in a rearward position wherein it maintains the mowerunit in its raised transport position; a stop means for limiting theforward movement of the control lever and thereby establishing thelowered operating position of the mower unit; and adjusting meansoperatively communicating with the stop means for selectively adjustingthe stop means and thereby vary the operating position of the mowerunit.

6. The invention defined in claim 5 wherein the stop means includes agenerally upright arm having its lower end pivotally connected to thelower end of the control lever by a transverse pivot and its upper endconnected to the supporting structure, an intermediate portion of saidarm engaging an abutment to limit the rearward movement of the lower endof the control lever.

7. The invention defined in claim 6 wherein the adjusting meansoperatively connects the upper end of said arm to the supportingstructure for selectively varying the position of the upper end of thearm and thereby varying the position of the lower end of the arm and thecontrol lever when the arm engages the abutment.

8. The invention defined in claim 7 wherein the adjusting means includesa fore-and-aft rod rotatably mounted in the supporting structure andhaving its forward end connected to the arm, and thread meansoperatively associated with the rod for shifting the arm in afore-and-aft direction in response to rotation of the rod.

9. The invention defined in claim 8 wherein the connecting means betweenthe control lever and the mower unit includes a cable trained around apulley on the main frame and having its forward end connected to thecontrol lever and its rearward end connected to the mower unit.

1. In a riding lawn mower having a mobile main frame supported on frontand rear wheels and a mower unit suspended from the main frame betweenthe front and rear wheels and including a generally horizontal housing,the improvement comprising: linkage means extending between the mainframe and the housing and operative to permit generally verticalmovement of the mower unit while maintaining it in a generallyhorizontal condition; a manually adjustable lever means mounted on themain frame for swinging in opposite generally fore-and-aft directions; acable means operatively interconnecting the lever means and the mowerunit so that the mower unit is raised in response to the movement of thelever means in one direction and lowered in response to movement in theopposite direction; latch means operatively associated with the levermeans for releasably locking the lever means in a raised positionwherein it maintains the mower unit in an elevated condition above theground; a stop means operatively communicating with the lever means forlimiting the movement of the lever means in said opposite direction andthereby establishing the lowermost position of the mower unit; andadjustment means operatively connected to the stop means for selectivelyadjusting the position of the stop means and varying the lowermostposition of the mower unit.
 2. The invention defined in claim 1 whereinthe stop means includes an abutment on the main frame and an adjustablemember connected to the lever means and engageable with the abutment tolimit the movement of the lever means, and the adjustment means isoperatively associated with said adjustable member to vary the positionof the adjustable member and thereby vary the position of the levermember when the adjustable member engages the abutment.
 3. The inventiondefined in claim 2 wherein the adjustable member is pivotally connectedto the lever means for swinging about an axis parallel to the levermeans pivot axis and the adjustment means includes a rotatable threadedrod operatively connected to the adjustable member for swinging themember about its pivot axis in response to rotation of the rod.
 4. Theinvention defined in claim 3 wherein the lever means includes agenerally upright control lever swingably mounted on a transverse pivotfor swinging in a fore-and-aft direction and the adjustable member isvertically elongated and has its lower end connected to the controllever and its upper end connected to the threaded rod for adjustment ina fore-and-aft direction, the control lever pivot forming the abutmentwhich engages an intermediate portion of the adjustable member to limitthe movement of the adjustable member and the control lever connectedthereto.
 5. In a riding mower having a mobile main frame including agenerally upright support structure at the forward end of the machineand a mower unit suspended from the frame via linkage means whichpermits vertical adjustment of the mower unit between a loweredoperating position and a raised transport position, the improvementcomprising: a generally upright control lever mounted on a transversepivot on the support structure for swinging in a fore-and-aft arc; aconnecting means between the lower end of the control lever and themower unit for respectively raising and lowering the mower unit inresponse to rearward and forward swinging of the control lever; alatching means for releasably holding the control lever in a rearwardposition wherein it maintains thE mower unit in its raised transportposition; a stop means for limiting the forward movement of the controllever and thereby establishing the lowered operating position of themower unit; and adjusting means operatively communicating with the stopmeans for selectively adjusting the stop means and thereby vary theoperating position of the mower unit.
 6. The invention defined in claim5 wherein the stop means includes a generally upright arm having itslower end pivotally connected to the lower end of the control lever by atransverse pivot and its upper end connected to the supportingstructure, an intermediate portion of said arm engaging an abutment tolimit the rearward movement of the lower end of the control lever. 7.The invention defined in claim 6 wherein the adjusting means operativelyconnects the upper end of said arm to the supporting structure forselectively varying the position of the upper end of the arm and therebyvarying the position of the lower end of the arm and the control leverwhen the arm engages the abutment.
 8. The invention defined in claim 7wherein the adjusting means includes a fore-and-aft rod rotatablymounted in the supporting structure and having its forward end connectedto the arm, and thread means operatively associated with the rod forshifting the arm in a fore-and-aft direction in response to rotation ofthe rod.
 9. The invention defined in claim 8 wherein the connectingmeans between the control lever and the mower unit includes a cabletrained around a pulley on the main frame and having its forward endconnected to the control lever and its rearward end connected to themower unit.